NEAR AND DISTANT SIGHT. 
321 
lias a certain flexibility and power to accommcdate itself for 
a short time to a glairs that does not quite suit it. But if the 
same degree of etFort is to be long continued, the eye tires 
and complains of an imperfection that was not at first perceived. 
It appeared to me, that so indisputable an improvement upon 
an instrument generally used, and, indeed, so necessary to 
many persons, deserved some public notice, and I advise those 
who ever use spectacles to make trial of these. If they are 
as well satisfied as I have reasoa to expect, they will derive a 
further gratification from reflecting, that the science which thus 
adds to our enjoyments of the objects immediately around us, 
is the same that has made us acquainted with the remotest parts 
of our solar system, and given us some conception of the im- 
mense extent of the universe. 
^ (Signed) BIOT, 
Member of the Imperial Institute^ 
IV. 
Dbservallo7is relative to the near and distant Sight of different 
Persons. By James Ware, Esq. F. R. S. From the Philo- 
sophical Transactions for 13\3. 
(^Concluded from p. 288.) 
I 
T appears to militate also against the common obsen’ation. 
that as near-sighted persons grow older, they become less Changes in the 
'lear-sighted j since my eyes, on the contrary, are more near- 
ighted, at the age of fifty-five, than they were at twenty-five; 
1 nd I am now' obliged to employ deeper concave glasses than I 
.'hen used to see distant objects, though I am not able to see 
I istinctly through them, things that are near*. 
The 
• It seems difficult to establish any rule (and, perhaps, there may be 
I ■one) according to which these changes in the eye take place. At 
SUPFLEMENT.— VoL. XXXVI.— No. I69. A i 
